15.10.4 Query Replace

M-% string <RET> newstring <RET>

Replace some occurrences of string with newstring.

C-M-% regexp <RET> newstring <RET>

Replace some matches for regexp with newstring.

If you want to change only some of the occurrences of ‘foo’ to
‘bar’, not all of them, use M-% (query-replace).
This command finds occurrences of ‘foo’ one by one, displays each
occurrence and asks you whether to replace it. Aside from querying,
query-replace works just like replace-string
(see Unconditional Replace). In particular, it preserves case
provided case-replace is non-nil, as it normally is
(see Replacement and Case). A numeric argument means to consider
only occurrences that are bounded by word-delimiter characters. A
negative prefix argument replaces backward.

C-M-% performs regexp search and replace (query-replace-regexp).
It works like replace-regexp except that it queries
like query-replace.

These commands highlight the current match using the face
query-replace. They highlight other matches using
lazy-highlight just like incremental search (see Incremental Search). By default, query-replace-regexp will show the
substituted replacement string for the current match in the
minibuffer. If you want to keep special sequences ‘\&’ and
‘\n’ unexpanded, customize
query-replace-show-replacement variable.

The characters you can type when you are shown a match for the string
or regexp are:

<SPC>

to replace the occurrence with newstring.

<DEL>

to skip to the next occurrence without replacing this one.

, (Comma)

to replace this occurrence and display the result. You are then asked
for another input character to say what to do next. Since the
replacement has already been made, <DEL> and <SPC> are
equivalent in this situation; both move to the next occurrence.

You can type C-r at this point (see below) to alter the replaced
text. You can also type C-x u to undo the replacement; this exits
the query-replace, so if you want to do further replacement you
must use C-x <ESC> <ESC> <RET> to restart
(see Repetition).

<RET>

to exit without doing any more replacements.

. (Period)

to replace this occurrence and then exit without searching for more
occurrences.

!

to replace all remaining occurrences without asking again.

Y (Upper-case)

to replace all remaining occurrences in all remaining buffers in
multi-buffer replacements (like the Dired <Q> command that performs
query replace on selected files). It answers this question and all
subsequent questions in the series with "yes", without further
user interaction.

N (Upper-case)

to skip to the next buffer in multi-buffer replacements without
replacing remaining occurrences in the current buffer. It answers
this question "no", gives up on the questions for the current buffer,
and continues to the next buffer in the sequence.

^

to go back to the position of the previous occurrence (or what used to
be an occurrence), in case you changed it by mistake or want to
reexamine it.

C-r

to enter a recursive editing level, in case the occurrence needs to be
edited rather than just replaced with newstring. When you are
done, exit the recursive editing level with C-M-c to proceed to
the next occurrence. See Recursive Edit.

C-w

to delete the occurrence, and then enter a recursive editing level as in
C-r. Use the recursive edit to insert text to replace the deleted
occurrence of string. When done, exit the recursive editing level
with C-M-c to proceed to the next occurrence.

e

to edit the replacement string in the minibuffer. When you exit the
minibuffer by typing <RET>, the minibuffer contents replace the
current occurrence of the pattern. They also become the new
replacement string for any further occurrences.

C-l

to redisplay the screen. Then you must type another character to
specify what to do with this occurrence.

C-h

to display a message summarizing these options. Then you must type
another character to specify what to do with this occurrence.

Some other characters are aliases for the ones listed above: y,
n and q are equivalent to <SPC>, <DEL> and
<RET>.

Aside from this, any other character exits the query-replace,
and is then reread as part of a key sequence. Thus, if you type
C-k, it exits the query-replace and then kills to end of
line.

To restart a query-replace once it is exited, use C-x
<ESC> <ESC>, which repeats the query-replace because it
used the minibuffer to read its arguments. See C-x ESC ESC.

See Operating on Files, for the Dired Q command which
performs query replace on selected files. See also Transforming File Names, for Dired commands to rename, copy, or link files by
replacing regexp matches in file names.